Modpack: ArdentCraft The Beginning (v. 3.1.01)
Mod version: 5.82 (release: 01/21/2017) (Can't seem to find a changelog for later versions, so I apologize if this has been fixed)

Description: I place the builder down, as a quarry, and power it with solar panels from Mekanism, connected via Ender IO Enhanced Energy Conduits. On top of the quarry, I have an EnderStorage ender chest. I use FTB Utilities to chunk load both the quarry and the solar generators.

After playing for a few hours, I notice that I'm no longer getting resources from the quarry. I hop over to where it is.. and the builder has vanished. This is the 4th time this has happened in the past two days.

I'm not sure what's going on here. I'm keeping an eye out, to see what could be causing the issue, but so far I've yet to see any cause. (And, no, the builder is not set up to quarry itself.)

um, that's weird. Is it only the builder that's gone or also the other blocks around it (like chest and such)? Do you perhaps have the option in forge.cfg enabled to remove crashing tile entities? If so there should be something in the log about this

Update: I stopped using FTB Utils to chunkload the chunk with the quarry itself, just in case, but I noticed that resources had, again, stopped coming in, so I went to my quarry.. and saw that the lever had fallen off the builder. I picked it up, stuck it back on, and switched the builder on.

The chest, as usual, is made of obnoxiously hard stuff, and has yet to brake. Same with everything else, sans the builder and, now, the lever.

A few hours later, I went to the quarry again, and this time both the builder and lever were on the ground.

Regarding the forge config:

B:removeErroringEntities=false
B:removeErroringTileEntities=false

I am having the same issue in Ardentcraft: The Beginning.

It has something to do with the Lycanite Mobs / Mountain mobs... As the builder and chest drop into items a Geonach is spawned at the location. So my conclusion was that it was the geonach who broke the builder, but even after disabing the Geonach in the config and deleting / recreating the chunks i still have the same problem.

For reference: TheBritishBrotherhood/ArdentCraft-The-Beginning#126